Drain valves are always positioned in the same place on a given tank and molded-in threaded inserts provide secure attachment points for a Flextank designed valve flange. These stainless steel flanges are made in high volume and provide a secure and cost effective attachment for butterfly valves. Includes 4" 10 Bolt Fitting, 4" Tri-Clamp, 4"Tri-Clamp Gasket, 4" Tri-Clamp Blank and Hex Wrench